Shuttle threading block



July 12, 1960 R. E. DASCH 2,944,572

SHUTTLE THREADING BLOCK Filed Sept. 26, 1951 INVENTOR. ROBERT E. DASCH ATTORN EY 2,944,572 a SHUTILE THREADING BLOCK Robert Eugene Das ch, Abington, Pa., assignor to Draper Corporation, Hopedale, Mass., a corporation of Maine Filed Sept. 26, 1957, Ser. No. sse,424 7 Claims. 01. 139-211 This invention pertains to improvements in threading blocks for loom shuttles. It is a general object of the invention to devise a threading'block for a loom shuttle which shall have improved filling tensioning means associated therewith and which shall be adapted to facilitate the weaving of all types of filling materials including those of highly elastic material such as the elastic or rubber yarns or various synthetic yarns adapted to be elongated rather extensively and which are woven'in ever-increasing quantities.

It is a more specific object of the invention to so devise a threading block for a shuttle adapted to weave these elastic or stretchable yarns and others of more conventional characteristics which'shall, apply to the filling the same tension throughout Weaving, that is, which shall apply tension at the first pick after transfer of the filling to the shuttle as is applied to the running thread at subsequent picks atwhich time the filling has become fully threaded. y

it is a more specific object of the invention to devise such a threading block which will through the use of more or less conventional tension pads and/or a special type of tension .pad located in a particular manner, take care of subjecting the filling to uniform tensions throughout the weaving process wholly automatically and in a manner which shall in no wise detract from the general efficacy of the filling block and shuttle of which it forms a part.

- Other objects will become apparent from the following more detailed disclosure. 1

In loom shuttles, especially those used in automatic looms, filling is threaded through a threading block, sometimes referred to 'as a shuttle eye, and this filling block serves the purpose of trapping the filling and of guiding it throughout the weaving operation. It is also so devised as to apply to the filling that tension effective in satisfactorily weaving cloth of desired quality.

In weaving cotton it is not customary to make any special provision for tensioning the filling, but in the weaving of silk and certain synthetics, tension must be applied as the filling is drawn through the threading block and several devices for accomplishing that purpose have been employed. The most common of these is the opposed spring pressed tension pads which are rather simple, inexpensive and also function well being adjustable to apply to the running thread any reasonable tension necessary therefor. These tension pads usually facilitate the threading of the filling as transfer is eifected so that-at the first pick after replenishment, the pads themselves as normally constructed and as normally applied in threading blocks subject the filling to that particular amount of tension for which they are designed.

Heretofore, weaving has been carried onwith the assumption that the tension due to drag on the material by these pads is so dominant that, in practice, if the filling enters the pads quickly after transfer, there-will be no noticeable distinction'between an initial pick and those subsequent. However, that is not wholly true and even in the case of cotton, there is more drag on the thread when fully threaded than when partially threaded at the first pick.

In weaving certain filling materials, for example, covered elastic yarn or certain other synthetic yarns including various types of nylon and the like, the stretch characteristics are such as to affect the running of the yarn verynoticeably and also, as the yarn passes around more corners and over a difierent number of friction points after becoming completely threaded, there is a very noticeable difference in tension on the yarn after the initial pick than at that pick. In other words the stretch in the filling makes more noticeable a given amount of tension difference. sion influences are employed they contribute tension of a particular value which does not vary from the first pick to subsequent picks, and since the inherent tension influences do vary very noticeably and are an important percentage of the total influence on the yarn, it becomes necessary to compensate for this or else fabric woven will show the particular points along its length at which introduction of a different yarn has been effected at transfer. a

7 According to a preferred form of the invention a more or less conventional shuttle threading block is employed having a body, a forwardly projecting horn and a side eye portion, the thread passing downwardly through a threading slot into a thread confining channel along the length of which one or more of the usual type of tension members may be positioned, these tension members preferably in the form of spring pressed tension pads being of such extent as to apply their retarding force to the filling once it becomes threaded at all and throughout the entire period of weaving. Outwardly or toward the end of the shuttle from the usual pad or pads is mounted a tensioning member which may, for example, be of similar form to the more standard type of pad but one which permits the filling to pass into and then downwardly from contact with the pads and the extent of which is limited to a level at which the filling travels during the first pick after replenishment. Preferably, this novel and additional tensioning member or members is or are positioned slightly forwardly of the side eye so that once the filling has become completely threaded at the start of the second pick after replenishment and is then running through the longitudinal channel and out the side eye, it will have moved beyond any possible influence of this extra tensioning'means and therefore cannot be affected thereby subsequently to the first pick.

The amount of tension necessarliy to be applied to the filling by the additional pads or other tensioning means must amount to approximately a value which compensates at the first pick for the added retarding infiuence on the yarn subsequent to the first pick. In other words, it adds to the tension of theyarn at the first pick an amount equal to that which will be added thereto by other influences after the first pick, and thus the retarding influence as the filling is drawn from the supply and laid in the shedat the initial pick of the shuttle after replenishment will be substantially the same in value as that at subsequent picks.

The invention will be described more fully hereinafter by reference to av specific embodiment thereof as illustrated in theaccompanying figures of drawing, wherein:

Fig. l is a plan view of part of a shuttle to which the novel threading block has been applied.

Fig. 2 is a side elevation of the shuttle and threading block of' Fig. l.

Fig. 3 is an elevational view taken from the front side If the usual appliedtenof the shuttle showing the threading block and especially the side eye mechanism thereof.

Fig. 4 is an end view of the threading block of Fig. 3, the view being taken from that end of the block located adjacent the tip of the shuttle when the parts are in assembled relationship.

Fig. 5 is a sectional view showing tensioning means applied in the block, this view being taken as though seen from the front of the shuttle looking toward the back.

Fig. 6 is a similar sectional view but showing parts as viewed from the opposite direction.

Now referring to Figs. 1 and 2, a shuttle 16 end is provided with the usual appurtenances including a tip 11, one at either end, and in the usual bobbin cavity carries a filling supply F on the bobbin the tip 12 of which is shown in this figure, parts at the opposite end being well known to those skilled in the art and not necessary of further illustration or explanation here. A threading block, sometimes referred to as a shuttle eye, and generally indicated by numeral 13 contains a body portion 14, a forwardly extending horn 15 having a downwardly bent thread confining lip 16 and apron 17 is mounted in a suitable recess or cavity adjacent the end of the shuttle and is held in place by the usual cross bolt 18. This shuttle block is provided with a longitudinal, more or less vertical cut or slot which constitutes a longitudinally extending, thread confining channel 19 within which the thread is passed downwardly as it is threaded at the transfer and also within the lower part of which the thread travels once it has become more completely threaded. A downwardly extending thread guiding portion 20 is adapted to cam the filling downwardly into a side eye generally indicated by numeral 21 in a manner well known to those skilled in the art. Likewise, this side eye is of more or less conventional construction and need not be described in greater detail here.

A threading block of this type is illustrated in United States Patent No. 2,379,650 and the general construction and arrangement of tension pads is also shown in that patent. The innermost group of pads designated by numeral 22, see particularly Figs. 5 and 6, are of full length being pivoted or jointed in place at the top at 23 and being loosely threaded on a cross pin 24 at their lower ends. Springs 25, of course, are locked in a suitable way to develop the proper amount of lateral pressure between the pads and once the filling has entered the pads at the top, it quickly moves down toward a central or running position and remains under the influence of these pads so long as weaving continues. The pads may be provided with scratches or inclined ridges of a type illustrated in United States Patent No. 2,046,287 in which case they are adapted to assist in the threading of the filling and in moving it more quickly to its running position.

While it is not necessary in all instances, in the particular embodiment of this invention herein illustrated and one which has been very successfully employed, a second set of pads 26 preferably of the same type as those at 22 are utilized so that the tension applied to the filling at all times is determined by the cumulative retarding effect applied thereon by the two sets of pads.

Adjacent the outer end of the block, that at which the filling passes down under the horn 15 being more or less trapped by the lip 16, a third or additional set of pads 2? includes opposed members 28 and 29 which are provided with lateral extensions, one at the top and also one at the bottom which are loosely engaged within drilled holes aligning therewith at adjacent parts of the block body. Springs 30 and 31 similar to those employed in pads of this general type are also adjustably retained in such a way that the pads may be caused to apply any reasonable and desired retarding influence on the filling. These pads are, as will be noted, shorter than those previously mentioned and actually their lower extremity is positioned well above the lower surface of the longitudinal thread channel and above the side eye 21. However, they are so positioned that the thread as shown in Figs. 1 and 2 as it runs in the shuttle at the first pick after transfer of the bobbin to the shuttle will actually pass more or less intermediate the ends of the pads and thus will be tensioned thereby at that pick in addition to being tensioned by the other pair or pairs of pads utilized.

These pads 28 and 29 are, however, so positioned forwardly of and above the side eye 21 that after the filling becomes completely threaded to emerge from side eye 21 at the second and subsequent picks, it moves downwardly and out of any possible influence by the extra and shorter set of pads. Thus from two points of view these pads are so positioned that they cannot be effective once the thread becomes completely threaded. They are also novel in that the thread may enter at the top and may pass downwardly and escape from the influence of the pads as it becomes completely threaded.

As shown in Figs. 1 and 2, the tension applied to the filling is pretty much limited to that due to the tensioning pads themselves there being very little friction otherwise encountered since the filling runs more or less in a general straight line or pathway from the supply F to the point outside the battery at which it may be anchored at that particular time. However, after coming completely threaded and having escaped from the influence of the extra and outer set of pads, tension or drag applied to the running filling is equal to the sum of that applied by the continuously effective pads such as those at 22 and 26 and also that due to the fact that the filling passes around certain surfaces preferably defined by hardened steel pins such as are commonly employed in shuttle blocks of this type and the edges of the side eye, etc., it being preferable, of course, in practice to adjust the various pads so that under each of these conditions the total drag will approach as closely to the same value as is practicable.

Preferred forms of the invention for use with silk, filament yarns, stretch yarns, covered elastic, etc., usually employ the conventional tension means and in addition, the novel pad strategically positioned as herein described. However, it is contemplated that with some filling mate'- rials the pads at the outer end of the block, that is, beyond and/or above the side eye may be the only added tension influence. A cotton eye might be so constructed and the pads would then supply extra tension at the first pick to balance the added, inherent drag on the thread when it passes through the side eye.

The term first pick as used herein refers to the first pick of a shuttle to which filling has been transferred after replenishment.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

l. A threading block for loom shuttles comprising a body having means defining a longitudinal thread channel, a side eye, a horn with a thread confining lip and a downwardly extending, thread guiding portion for camming the thread into the side eye, tension pads resiliently pressed into thread tensioning engagement positioned to affect said thread once it becomes threaded in said block, and a second tension means by which said thread is engaged and tensioned upon the first pick of a shuttle of which said block is a part, said second tension means being so limited in extent and so positioned that .the thread becomes entirely disengaged therefrom upon entering the said side eye and becoming fully threaded.

2. A threading block .for loom shuttles comprising a body having means defining a longitudinal thread chan-' nel, a side eye, a horn with a thread confining lip and a downwardly extending, thread guiding portion for camming the thread into the side eye, tension pads resiliently pressed into thread tensioning engagement positioned to affect said thread once it becomes threaded in said block, and a second tensioning means eifective upon said thread at a first pick only of a shuttle of which said block is a part, which means comprises opposed tensioning pads, resilient means for pressing said pads into tensioning engagement with the thread, said pads further being positioned entirely above a plane at which, said thread is drawn through the block after said first pick and upon becoming fully threaded.

3. A threading block for loom shuttles comprising a body having means defining a longitudinalthread channel, a side eye, a horn with a thread confining lip and a downwardly extending, thread guiding portion for camming the thread into the side eye, tension pads resiliently pressed into thread tensioning engagement positioned to affect said thread once it becomes threaded in said block, and a second tensioning means efiective upon said thread at a first pick only of a shuttle of which said block is a part, which means comprises opposed tensioning pads, resilient means for pressing said pads into tensioning engagement with the thread, said pads further being positioned farther toward the horn end of said block than any point reached by the running thread once it has become plenishment.

4. A threading blockfor loom shuttles comprising a body having means defining a longitudinal thread channel, a side eye, a horn with a thread confining lip and a downwardly extending, thread guiding portion for camming the thread into the side eye, the construction being are positioned above the plane of the side eye.

6. Mechanism as defined in claim 4 wherein said pads are positioned beyond the position of said side eye in the direction of the horn of the block.

7. Mechanism as defined in claim 4 wherein said pads are positioned both above and beyond the position of said side eye.

References Cited in the file of this patent UNITED STATES PATENTS 2,004,721 Fuller June 11, 1935 2,125,405 Tebo Aug. 2, 1938 2,379,650 Nichols July 3, 1945 2,663,327 Carrigan Dec. 22, 1953 2,810,404 Chalmers et al. Oct. 22, 1957 

